In the proposed continuation project, attempts will be made to harvest anti-glucagon sera of high affinity and specificity from rabbits and guinea pigs which have been immunized with a glucagon-keyhole limpet hemocyanine conjugate. The affinity and specificity of the antisera already collected, as well as that produced after subsequent booster injections, will be determined using native glucagon and specific glucagon fragments. Using high quality glucagon antisera, we will then begin to assess regulation of glucagon release. Measurements of released and tissue-sequestered glucagon will be made by a radioimmunoassay optimized for the antisera produced.